Conventional watch movements include tourbillons in which the rotation axis of the balance wheel is arranged either parallel or perpendicular to the rotation axis of the tourbillon platform. In addition, tourbillons are known in which the rotation axis of the balance wheel is arranged at an angle to the rotation axis of the platform. The purpose of these devices is to prevent the positional inaccuracy of the balance wheel caused by overlapping motions. A very complicated example of a tourbillon is Walter Prendel's flying tourbillon created in 1928 (cf. http://www.network54.com). In that tourbillon, both the balance wheel and the escapement are disposed obliquely to the rotation axis of the tourbillon platform. The escapement is coupled to the balance wheel by a plurality of mechanical connections (gear pairs), resulting in a fascinating mechanism. However, a commercial implementation of Walter Prendel's flying tourbillon is not practical, due to its complicated structure.
EP1564608 discloses a tourbillon supported on both sides and in which the balance wheel and the escapement are disposed obliquely to the rotation axis of the platform. To ensure that the largest possible balance wheel results, the rotation axis of the balance wheel and the rotation axis of the rotating frame are arranged in one plane. Furthermore, the rotation axes of the escapement and of the balance wheel are arranged in parallel to one another. In order for the escape-wheel, which is arranged on the tourbillon platform, to rotate, it must be operatively linked to a fixed base. This is accomplished by means of a gear wheel with helical teeth. However, the manufacture of the gear wheel requires a relatively large outlay. Furthermore, straight teeth are easier to manufacture than helical teeth and may prevent gear hobbing caused by helical teeth. Additional problems arise from increased wear and tear owing to the surface unit pressure.
CH694598 discloses a multiple-axis tourbillon in which the balance wheel is arranged in a cage and rotates about three axes. This tourbillon also has a very complex design that ultimately provides little advantage with regard to accuracy.